282:. Each of these three used its own additional command-sets instead of waiting for Hayes to lead the way. By the early-1990s, there were four major command sets in use, and a number of versions based on one of these. Things became simpler again during the widespread introduction of 14.4 and 28.8 kbit/s modems in the early 1990s. Slowly, a set of commands based heavily on the original Hayes extended set using "&" commands became popular, and then universal. Only one other command set has remained popular, the U.S. Robotics set from their popular line of modems.
1558:. A V.250 compliant modem implements the A, D, E, H, I, L, M, N, O, P, Q, T, V, X, Z, &C, &D, and &F commands in the way specified by the standard. It must also implement S registers and must use registers S0, S3, S4, S5, S6, S7, S8, and S10 for the purposes given in the standard. It also must implement any command beginning with the plus sign, "+" followed by any letter A to Z, only in accordance with ITU recommendations. Modem manufacturers are free to implement other commands and S-registers as they see fit, and may add options to standard commands.
31:
1813:(PPP) for the data connection because of performance reasons (PPP connection is only used between the computer and the modem, not over network). The set-up requires vendor-specific AT command extensions. Sometimes the specifications for these extensions are openly available, other times the vendor requires an NDA for access to these.
162:
and receiving commands, another could have used a signal pin indicating that the modem should interpret incoming data as a command. Both of these had hardware support in the RS-232 standard. However, many implementations of the RS-232 port on microcomputers were extremely basic, and some eliminated many of these pins to reduce cost.
366:
Optional subparameter of a command or an optional part of AT information response is enclosed in square brackets. Brackets themselves do not appear in the command line. When the subparameter is not given in AT commands which have a Read command, the new value equals its previous value. In AT commands
161:
needed a way to tell the modem what number to dial through software. The earlier separate dialers had this capability, but only at the cost of a separate port, which a microcomputer might not have available. Another solution would have been to use a separate set of "command pins" dedicated to sending
129:
When automation was required, it was commonly only needed on the answer side; for instance, a bank might need to take calls from a number of branch offices for end-of-day processing. To fill this role, some modems included the ability to pick up the phone automatically when it was in answer mode, and
595:
As a result of all this, eventually many communications programs had to give up any sense of being able to talk to all "Hayes-compatible" modems, and instead the programs had to try to determine the modem type from its responses, or provide the user with some option whereby they could enter whatever
590:
modems had serious quirks that made them effectively incompatible. For example, many modems required a pause of several seconds after receiving the "AT Z" reset command. Some modems required spaces between commands, while others did not. Some would unhelpfully change baud-rate of their own volition,
125:
that began and ended with a known modem at each end. The modems operated in either "originate" or "answer" modes, manually switching between two sets of frequencies for data transfer. Generally, the user placing the call would switch their modem to "originate" and then dial the number by hand. When
332:
can return the modem to command mode. The normal escape sequence is three plus signs ("+++"), and to disambiguate it from possible real data, a guard timer is used: it must be preceded by a pause, not have any pauses between the plus signs, and be followed by a pause; by default, a "pause" is one
250:
The expansion to 1200 and 2400 baud required the addition of a small set of new commands, some of them prefixed with an ampersand ("&") to denote those dedicated to new functionality. Hayes itself was forced to quickly introduce a 2400 baud model shortly after their 1200, and the command sets
153:
of the 1970s led to the introduction of low-cost modems and the idea of a semi-dedicated point-to-point link was no longer appropriate. There were potentially thousands of users who might want to dial any of the other thousands of users, and the only solution at the time was to make the user dial
354:
Linefeed character, is the character recognised as line feed character. Its value, in decimal ASCII between 0 and 255, is specified in register S4. The default value is 10. The line feed character is output after the carriage return character if verbose result codes are used (V1 option is used);
410:
software. Terminal-emulator software typically allows the user to send Hayes commands directly to the modem, and to see the responses. In this example, the user of computer A makes the modem dial the phone number of modem B at phone number (212) 555-0100 (long distance). After every command and
76:
The command set covered only those operations supported by the earliest 300 bit/s modems. When new commands were required to control additional functionality in higher speed modems, a variety of one-off standards emerged from each of the major vendors. These continued to share the basic command
494:
When the modems are connected, any characters typed at either side will appear on the other side. The person at computer A starts typing. The characters pass through the modem and appear on computer B's screen. (User A may not see his own typed characters — depending on the terminal software's
574:
Due to the lack of a written standard, other modem manufacturers just copied the external visible commands and (roughly) the basic actions. This led to a wide variety of subtle differences in how modems changed from state to state, and how they handled error conditions, hangups, and
578:
Each manufacturer tended to add new commands to handle emerging needs, often incompatible with other modems. For example, setting up hardware or software handshaking often required many different commands for different modems. This undermined the handy universality of the basic
72:
The command set consists of a series of short text strings which can be combined to produce commands for operations such as dialing, hanging up, and changing the parameters of the connection. The vast majority of dial-up modems use the Hayes command set in numerous variations.
224:
security implication in that it would lead to the modem hanging up the connection should the computer ever try to transmit the byte sequence "+++ATH0" in data mode. For any computer connected to the
Internet through such a modem, this could be easily exploited by sending it a
478:
The modems connect, and both modems report "connect". (In practice, most modems report more information after the word CONNECT — specifying the speed of the connection.) Also, at this time, both modems will raise the DCD, or Data
Carrier Detect signal, on the serial port.
246:
which allowed the user to directly set the various memory locations in the original Hayes modem. The command set was copied largely verbatim, including the meaning of the registers, by almost all early 300 baud modem manufacturers, of which there were quite a few.
251:
were identical as a time-saving method. Essentially by accident, this allowed users of existing 1200 baud modems to use the new Hayes 2400 models without changing their software. This re-inforced the use of the Hayes versions of these commands. Years later, the
803:
This command returns information about the model, such as its firmware or brand name. Each number (0 to 9, and sometimes 10 and above) returns one line of modem-specific information, or the word ERROR if the line is not defined. Today, Windows uses this for
1808:
Most USB modem vendors, such as Huawei, Sierra
Wireless, Option, have also defined proprietary extensions for radio mode selection (GSM/3G preference) or similar. Some recent high speed modems provide a virtual Ethernet interface instead of using a
130:
to clear the line when the other user manually disconnected. The need for automated outbound dialling was considerably less common, and was handled through a separate peripheral device: a "dialler". This was normally plugged into a separate
229:
request containing the sequence "+++ATH0" in the payload. The computer operating system would automatically try to reply the sender with the same payload, immediately disconnecting itself from the
Internet, as the modem would interpret the
608:
as "A" and "T" happen to have bit patterns that are very regular; "A" is "100 0001" and so has a 1 bit at the start and end and "T" is "101 0100" which has a pattern with (nearly) every other bit set. Since the RS-232 interface transmits
367:
which do not store the values of any of their subparameters, and so have not a Read command, which are called action type commands, the action should be done on the basis of the recommended default setting of the subparameter.
324:
Although the command-set syntax defines most commands by a letter-number combination (L0, L1 etc.), the use of a zero is optional. In this example, "L0" equates to a plain "L". Keep this in mind when reading the table below.
511:
The person at computer B issues the modem escape command. (Alternately, and more commonly, the computer B could drop the DTR, or Data
Terminal Ready signal, to achieve a hangup, without needing to use +++ or ATH.)
823:
Speaker
Loudness. Supported only by some modems with speakers. Modems lacking speakers, or with physical volume controls, or ones whose sound output is piped through the sound card will not support this command.
314:
represents a specific physical location in memory. Modems have small amounts of memory on board. The fourth set of commands serves for entering values into a particular register (memory location). For example,
319:
instructs the modem to "Set register #7 to the value 60". Registers usually control aspects of the modem operation (e.g. transmission strength, modulation parameters) and are usually specific to a particular
304:
extended command set – An "&" (ampersand) and a capital character followed by a digit. This extends the basic command set. For example, &M1. Note that M1 is different from &M1.
176:
Hayes
Communications introduced a solution in its 1981 Smartmodem by using the existing data pins with no modification. Instead, the modem itself could be switched between one of two modes:
348:
Carriage return character, is the command line and result code terminator character, which value, in decimal ASCII between 0 and 255, is specified in register S3. The default value is 13.
234:
packet's data payload as a Hayes command. The same error would also trigger if, for example, the user of the computer ever tried to send an e-mail containing the aforementioned string.
242:
The Hayes command set includes commands for various phone-line operations such as dialing and hanging-up. It also includes various controls to set up the modem, including a set of
2121:
213:
command, "ATO". In actual use many of the commands automatically switched to the online mode after completion, and it is rare for a user to use the online command explicitly.
185:
in which the modem sends the data to the remote modem. (A modem in data mode treats everything it receives from the computer as data and sends it across the phone line).
2140:
2248:
566:
While the original Hayes command set represented a huge leap forward in modem-based communications, with time many problems set in, almost none of them due to Hayes
126:
the remote modem answered, already set to "answer" mode, the telephone handset was switched off and communications continued until the caller manually disconnected.
209:: if any other data was received within one second of the three plus signs, it was not the escape sequence and would be sent as data. To switch back they sent the
205:
string of three plus signs ("+++") followed by a pause of about a second. The pause at the end of the escape sequence was required to reduce the problem caused by
2235:
307:
proprietary command set – Usually starting either with a backslash (“\”) or with a percent sign (“%”); these commands vary widely among modem manufacturers.
859:
Speaker on until remote carrier detected (user will hear dialing and the modem handshake, but once a full connection is established the speaker is muted)
270:
However, Hayes
Communications were slow to release modems supporting higher speeds or compression, and three other companies led the way here —
1995:
1805:
GSM/3G modems typically support the ETSI GSM 07.07/3GPP TS 27.007 AT command set extensions, although how many commands are implemented varies.
294:: "AT" meaning 'attention'. Each command string is prefixed with "AT", and a number of discrete commands can be concatenated after the "AT".
141:
This method of operation worked satisfactorily in the 1960s and early 1970s, when modems were generally used to connect dumb devices like
1827:
Modems with voice or answering-machine capabilities support a superset of these commands to enable digital audio playback and recording.
1177:
is similar in that it returns to factory default settings on modems without NVRAM (non volatile memory), but it does not reset the modem
2182:
2125:
406:
The following represents two computers, computer A and computer B, both with modems attached, and the user controlling the modems with
2262:
2187:
2294:
390:, which was typically a long concatenated AT command which was sent to the modem upon launch. The V.250 specification requires all
2257:
1753:
252:
216:
In order to avoid licensing Hayes's patent, some manufacturers implemented the escape sequence without the time guard interval (
2316:
310:
register commands – Sr=n where r is the number of the register to be changed, and n is the new value that is assigned. A
2367:
194:
551:
Both modems report that the connection has ended. Modem B responds "OK" as the expected result of the command; modem A says
2147:
1165:
Reset modem to stored configuration, and usually also physically power-cycles the modem (during which it is unresponsive).
376:
A string can contain many Hayes commands placed together, so as to optimally prepare the modem to dial out or answer, e.g.
2245:
59:
1773:
2195:
439:
User at modem A issues a dial command: AT-Get the modem's ATtention; D-Dial; T-Touch-Tone; 12125550100-Call this number
2220:
2023:
1198:
causes many applications to pause sending the command stream to the device (usually for half a second), e.g. after a
231:
17:
555:
to report that the remote side interrupted the connection. The modems on both sides drop their DCD signals as well.
2229:
1887:
217:
756:
Will echo commands to the computer (so one can see what one types if the computer software does not support echo)
647:
The following commands are understood by virtually all modems supporting an AT command set, whether old or new.
1842:
1718:
1543:
355:
otherwise, if numeric format result codes are used (V0 option is used), it will not appear in the result codes.
256:
189:
181:
2287:
2165:
605:
2336:
391:
93:, for instance. Many of these were re-standardized on the Hayes extensions after the introduction of the
2204:
1992:
888:
Returns the modem back to the normal connected state after being interrupted by the "+++" escape code.
171:
55:
77:
structure and syntax, but added any number of new commands using some sort of prefix character –
2280:
1949:
221:
150:
1764:
List available networks 0-Unknown/2-Current/3-Forbidden, Longname, Shortname, Numerical-ID, "AcT"
1690:
2212:
2011:
1822:
1810:
1797:
1693:
phone or modem. The ETSI GSM 07.05 (3GPP TS 27.005) specifies AT style commands for managing the
361:
Name enclosed in angle brackets is a syntactical element. They do not appear in the command line.
2097:
1582:
Call control (network
Addressing) issues, common, PSTN, ISDN, ITU-T Rec. X.25, switched digital
1911:
1694:
610:
118:
1964:
261:
Data
Transmission Systems and Equipment – Serial Asynchronous Automatic Dialing and Control
1550:, in 1995 in an attempt to establish a standard for the command set again. It was renamed
8:
94:
1892:
311:
146:
51:
1836:
407:
206:
158:
142:
2272:
451:
Modem A begins dialing. Modem B's phone-line rings, and the modem reports the fact.
496:
47:
1689:
The ETSI GSM 07.07 (3GPP TS 27.007) specifies AT style commands for controlling a
1120:
Usually adds dial tone detection (preventing blind dial, and sometimes preventing
301:
basic command set – A capital character followed by a digit. For example, M1.
2362:
2252:
2224:
2199:
1999:
1777:
412:
329:
202:
2240:
2073:
596:
special commands it took to coerce their particular modem into acting properly.
1554:
in 1998 with an annex that was not concerning the Hayes command set renamed as
1433:
0–255 (seconds if synchronous mode, hundredths of a second in all other modes)
122:
30:
2056:
V.250 : Serial asynchronous automatic dialling and control (05/99, 07/03)
2356:
2192:
1934:
805:
723:! – Flash switch-hook (Hang up for a half second, as in transferring a call.)
395:
275:
259:(EIA) raised the 2400-baud command set into a formal standard with the title
226:
591:
which would leave the computer with no clue how to handle the incoming data.
2217:
2027:
131:
1032:
on its own will store into whichever register was most recently selected.
2048:
290:
The following text lists part of the Hayes command set, also called the
2321:
1071:
552:
82:
2122:"Developers guidelines June 2010 AT commands for Sony Ericsson phones"
2326:
994:
on its own will query whichever register was most recently selected.
786:
Off hook. Picks up the phone line (typically you'll hear a dialtone)
958:
are actually three separate commands, and can be given in separate
719:, - Pause for the time specified in register S8 (usually 2 seconds)
636:
271:
90:
1969:
279:
2331:
922:
On – Result codes are suppressed, user does not see responses.
905:
Off – Displays result codes, user sees command responses (e.g.
135:
2133:
1183:
Note: a command string is terminated with a CR (\r) character
2304:
2266:
2059:
1853:
1847:
1539:
1187:
615:
104:" was and as of 2018 still is important within the industry.
66:
693:, do not follow with carriage return. Enter usually aborts.
2208:
2166:"Dan Williams' blog – That's when I reach for my revolver…"
394:
to accept a body (after "AT") of at least 40 characters of
201:
To switch from data mode to command mode, sessions sent an
63:
2158:
1104:
Usually adds connection speed to basic result codes (e.g.
773:
On hook. Hangs up the phone, ending any call in progress.
2183:
List of AT commands: Basic (Hayes), Extended, Proprietary
1860:
827:
0 turns off speaker, 1 to 3 are for increasing volumes.
717:@ - Wait for up to 30 seconds for one or more ringbacks
138:
port) and programmed separately from the modem itself.
1148:
Usually adds both busy signal and dial tone detection
297:
The Hayes command set can subdivide into four groups:
2302:
2116:
2114:
990:
as the current register, and query its value. Using
536:The person at computer B issues a hang up command.
2111:
1912:"The Modem of Dennis Hayes and Dale Heatherington"
649:
619:(eight data bits, no parity bit, one stop bit) is
1622:Generic issues such as identity and capabilities
1194:is commonly used in modem command sequences. The
2354:
1885:
1630:DTE-DCE Interface issues, ITU-T Rec. V.24, etc.
386:. Most modem software supported a user supplied
197:modem (commands the local modem should execute).
193:in which data is interpreted as commands to the
121:(BBS), modems typically operated on direct-dial
2024:"Initialization Strings: Why, What & Where"
1881:
1879:
1209:
871:Speaker always on (data sounds are heard after
841:Speaker Mute, completely silent during dialing
642:
2288:
1092:Hayes Smartmodem 300 compatible result codes
847:is also common, but different on many brands
341:The following syntactical definitions apply:
2230:Extended Hayes AT command parameters for SMS
1876:
706:Dial the following number and then handshake
97:and the market consolidation that followed.
1563:V.250 – Defined leading character sequences
463:Computer at modem B issues answer command.
2295:
2281:
1909:
1499:7 Attempt to connect in V.23 75/1200 mode.
1374:Delay between Loss of Carrier and Hang-Up
336:
2062:/Telecommunication Standardization Bureau
2041:
721:; – Remain in command mode after dialing.
1993:"The AT Command Set Reference – History"
1950:"How to Set Up a Hayes Compatible Modem"
1186:Although not part of the command set, a
715:R – Reverse to answer-mode after dialing
333:second and "no pause" is anything less.
29:
1869:
1772:Get signal strength. Answer: +CSQ: <
1752:Status (Manufacturer, Model, Revision,
1173:etc. are for multiple stored profiles.
800:Inquiry, Information, or Interrogation
743:Will not echo commands to the computer
613:first, the according line pattern with
371:
253:Telecommunications Industry Association
14:
2355:
1638:Modulation, ITU-T Rec. V.32 bis, etc.
1598:Data Compression, ITU-T Rec. V.42 bis
2276:
2236:Determining your Class of Fax / Modem
1888:"The Rise and Fall of the Modem King"
1793:AT+CGDCONT=1,"IP","access.point.name"
1886:Victoria Shannon (January 7, 1999).
1816:
1728:Change PIN code from 'old' to 'new'
1654:Switched or Simultaneous Data Types
1508:10 Attempt to connect at 14400 bit/s
1136:Usually adds busy signal detection.
2049:"5.2.1 Command line general format"
1962:
1505:9 Attempt to connect at 12000 bit/s
1234:Number of rings before Auto-Answer
1019:as the current register, and store
808:detection of specific modem types.
134:port on the computer (typically an
24:
1646:PCM DCE commands, ITU-T Rec. V.92
1502:8 Attempt to connect at 9600 bit/s
1496:6 Attempt to connect at 2400 bit/s
1493:5 Attempt to connect at 1200 bit/s
1346:Pause Time for Comma (Dial Delay)
604:The Hayes command set facilitated
401:
165:
25:
2379:
2188:Hayes AT Command Reference Manual
2176:
2130:090505 developer.sonyericsson.com
1614:Facsimile, ITU-T Rec. T.30, etc.
1490:3 Attempt to connect at 300 bit/s
1487:2 Attempt to connect at 300 bit/s
1484:1 Attempt to connect at 300 bit/s
713:W – Wait for the second dial tone
1963:Max, Schau (27 September 1998).
561:
218:Time Independent Escape Sequence
2090:
2066:
1965:"1+2=3, +++ATH0=Old school DoS"
1606:Error Control, ITU-T Rec. V.42
1318:Wait Time before Blind Dialing
364:
358:
351:
345:
117:Before the introduction of the
2317:ITU-T V-series recommendations
2016:
2005:
1985:
1956:
1942:
1925:
1903:
1843:Command and Data modes (modem)
1542:established a standard in its
1521:Delay before Force Disconnect
1481:0 Attempt auto mode connection
415:sent to complete the command.
285:
257:Electronic Industries Alliance
13:
1:
2141:"UC864-E Software User Guide"
1938:. March 30, 1987. p. 61.
1574:Includes commands related to
1447:0–255 hundredths of a second
1360:Carrier Detect Response Time
606:automatic baud rate detection
112:
2368:Hayes Microcomputer Products
1590:Digital Cellular extensions
1458:Inactivity Disconnect Timer
1405:0–255 fiftieths of a second
1332:Wait for Carrier after Dial
1210:Modem S register definitions
7:
2263:AT Commands Reference Guide
2218:Modem initialisation string
2193:A list of Hayes AT commands
2012:AT Commands Reference Guide
1830:
1061:English result codes (e.g.
643:The basic Hayes command set
599:
524:The modem acknowledges it.
237:
10:
2384:
1820:
1700:Examples of GSM commands:
1444:RTS to CTS Delay Interval
1363:1–255 tenths of a seconds
1276:Carriage Return Character
1206:is not sent to the modem.
220:(TIES)). This had a major
172:Command mode and Data mode
169:
149:(answering). However, the
145:(dialling out) with smart
107:
27:Command language for modem
2312:
1472:Desired Telco Line Speed
1377:1–255 tenths of a second
936:
34:Hayes 300 Baud Smartmodem
2155:090505 m2m-platforms.com
2100:. Chebucto Community Net
1725:AT+CPWD="SC","old","new"
1544:V-Series Recommendations
1533:
1450:1 hundredth of a second
970:as the current register
937:Select current register
151:microcomputer revolution
50:originally developed by
1823:Voice modem command set
1811:Point-to-Point Protocol
1776:(more=better)>, <
1402:Escape Code Guard Time
337:Syntactical definitions
1697:(SMS) feature of GSM.
1684:
1461:0–255 tens of seconds
328:When in data mode, an
35:
2241:Openmoko: AT Commands
2098:"More Modem Commands"
1733:AT+CLCK="SC",0,"1234"
1695:Short Message Service
1293:0–127, ASCII decimal
1282:13 (Carriage Return)
1279:0–127, ASCII decimal
1265:0–255, ASCII decimal
1049:Numeric result codes
725:L – Dial last number
673:Answer incoming call
631:(start and stop bits
611:least significant bit
411:response, there is a
388:initialization string
170:Further information:
119:Bulletin Board System
33:
2342:Hayes AT command set
1932:"Hayes compatible".
1870:Notes and references
1678:Wireless extensions
1391:50–255 milliseconds
1307:0–32, ASCII decimal
1304:Backspace Character
1290:Line Feed Character
689:Do not preface with
686:Repeat last command
372:Modem initialization
2246:Cell modem commands
2211:AT command set for
2074:"Serial Interfaces"
1565:
1388:DTMF Tone Duration
711:T – Touch Tone Dial
635:) which is used as
147:mainframe computers
95:SupraFAXModem 14400
42:(also known as the
2303:Telephone network
2258:ITU Standard V.250
2251:2007-10-28 at the
2223:2009-03-10 at the
2198:2008-07-10 at the
1998:2008-04-15 at the
1893:The New York Times
1788:Dial access point
1780:, less=better>
1561:
1237:0–255 (0 = never)
143:computer terminals
52:Dale Heatherington
36:
2350:
2349:
1850:Recommendations:
1837:Access Point Name
1817:Voice command set
1803:
1802:
1682:
1681:
1670:Voice extensions
1531:
1530:
1477:Command options:
1380:14 (1.4 seconds)
1262:Escape character
1181:
1180:
581:Hayes command set
559:
558:
408:terminal-emulator
244:register commands
222:denial of service
207:in-band signaling
159:computer industry
40:Hayes command set
18:Hayes command set
16:(Redirected from
2375:
2297:
2290:
2283:
2274:
2273:
2170:
2169:
2162:
2156:
2154:
2152:
2146:. Archived from
2145:
2137:
2131:
2129:
2124:. Archived from
2118:
2109:
2108:
2106:
2105:
2094:
2088:
2087:
2085:
2084:
2070:
2064:
2063:
2053:
2045:
2039:
2038:
2036:
2035:
2026:. Archived from
2020:
2014:
2009:
2003:
1991:Frank Durda IV,
1989:
1983:
1982:
1980:
1978:
1960:
1954:
1953:
1952:. June 17, 2018.
1946:
1940:
1939:
1929:
1923:
1922:
1920:
1918:
1910:Georgi Dalakov.
1907:
1901:
1900:
1883:
1756:, capabilities)
1736:Remove PIN code
1703:
1702:
1566:
1560:
1394:95 milliseconds
1214:
1213:
1107:
1074:
1068:
1064:
1029:
1015:Select register
1010:
1004:
986:Select register
980:
966:Select register
956:
945:
932:
908:
874:
650:
588:Hayes compatible
418:
417:
385:
365:
360:
353:
347:
102:Hayes compatible
88:
80:
60:Hayes Smartmodem
48:command language
46:) is a specific
21:
2383:
2382:
2378:
2377:
2376:
2374:
2373:
2372:
2353:
2352:
2351:
2346:
2308:
2301:
2253:Wayback Machine
2225:Wayback Machine
2200:Wayback Machine
2179:
2174:
2173:
2164:
2163:
2159:
2150:
2143:
2139:
2138:
2134:
2120:
2119:
2112:
2103:
2101:
2096:
2095:
2091:
2082:
2080:
2072:
2071:
2067:
2051:
2047:
2046:
2042:
2033:
2031:
2022:
2021:
2017:
2010:
2006:
2000:Wayback Machine
1990:
1986:
1976:
1974:
1961:
1957:
1948:
1947:
1943:
1931:
1930:
1926:
1916:
1914:
1908:
1904:
1884:
1877:
1872:
1833:
1825:
1819:
1687:
1570:
1564:
1536:
1366:6 (0.6 second)
1296:10 (Line Feed)
1212:
1105:
1070:
1066:
1062:
1027:
1008:
1002:
978:
954:
943:
930:
906:
872:
724:
722:
720:
718:
716:
714:
712:
710:
707:
645:
602:
564:
433:ATDT12125550100
413:carriage return
404:
402:Example session
377:
374:
339:
330:escape sequence
288:
240:
203:escape sequence
174:
168:
166:Hayes' solution
123:telephone lines
115:
110:
86:
78:
28:
23:
22:
15:
12:
11:
5:
2381:
2371:
2370:
2365:
2348:
2347:
2345:
2344:
2339:
2334:
2329:
2324:
2319:
2313:
2310:
2309:
2300:
2299:
2292:
2285:
2277:
2271:
2270:
2260:
2255:
2243:
2238:
2233:
2227:
2215:
2213:User Equipment
2202:
2190:
2185:
2178:
2177:External links
2175:
2172:
2171:
2157:
2153:on 2011-07-14.
2132:
2128:on 2011-09-29.
2110:
2089:
2065:
2040:
2015:
2004:
1984:
1955:
1941:
1924:
1902:
1898:with a partner
1874:
1873:
1871:
1868:
1867:
1866:
1865:
1864:
1857:
1845:
1840:
1832:
1829:
1821:Main article:
1818:
1815:
1801:
1800:
1794:
1790:
1789:
1786:
1782:
1781:
1770:
1766:
1765:
1762:
1758:
1757:
1750:
1746:
1745:
1742:
1738:
1737:
1734:
1730:
1729:
1726:
1722:
1721:
1715:
1711:
1710:
1707:
1686:
1683:
1680:
1679:
1676:
1672:
1671:
1668:
1664:
1663:
1660:
1656:
1655:
1652:
1648:
1647:
1644:
1640:
1639:
1636:
1632:
1631:
1628:
1624:
1623:
1620:
1616:
1615:
1612:
1608:
1607:
1604:
1600:
1599:
1596:
1592:
1591:
1588:
1584:
1583:
1580:
1576:
1575:
1572:
1562:
1535:
1532:
1529:
1528:
1525:
1524:0–255 seconds
1522:
1519:
1515:
1514:
1511:
1510:
1509:
1506:
1503:
1500:
1497:
1494:
1491:
1488:
1485:
1482:
1473:
1470:
1466:
1465:
1462:
1459:
1456:
1452:
1451:
1448:
1445:
1442:
1438:
1437:
1434:
1431:
1428:
1424:
1423:
1420:
1419:0–255 seconds
1417:
1414:
1410:
1409:
1408:50 (1 second)
1406:
1403:
1400:
1396:
1395:
1392:
1389:
1386:
1382:
1381:
1378:
1375:
1372:
1368:
1367:
1364:
1361:
1358:
1354:
1353:
1350:
1349:0–255 seconds
1347:
1344:
1340:
1339:
1336:
1335:1–255 seconds
1333:
1330:
1326:
1325:
1322:
1321:2–255 seconds
1319:
1316:
1312:
1311:
1310:8 (Backspace)
1308:
1305:
1302:
1298:
1297:
1294:
1291:
1288:
1284:
1283:
1280:
1277:
1274:
1270:
1269:
1266:
1263:
1260:
1256:
1255:
1252:
1249:
1246:
1242:
1241:
1238:
1235:
1232:
1228:
1227:
1226:Default value
1224:
1221:
1218:
1211:
1208:
1179:
1178:
1163:
1160:
1150:
1149:
1146:
1144:
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1134:
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1126:
1125:
1118:
1116:
1110:
1109:
1102:
1100:
1094:
1093:
1090:
1087:
1077:
1076:
1059:
1057:
1051:
1050:
1047:
1044:
1034:
1033:
1013:
996:
995:
984:
972:
971:
964:
935:
924:
923:
920:
917:
911:
910:
903:
900:
890:
889:
886:
885:Return Online
883:
877:
876:
869:
867:
861:
860:
857:
855:
849:
848:
842:
839:
829:
828:
825:
821:
810:
809:
801:
798:
788:
787:
784:
781:
775:
774:
771:
768:
758:
757:
754:
751:
745:
744:
741:
738:
728:
727:
709:P – Pulse Dial
704:
701:
695:
694:
687:
684:
678:
677:
674:
671:
661:
660:
657:
654:
644:
641:
601:
598:
593:
592:
584:
576:
563:
560:
557:
556:
549:
544:
538:
537:
534:
529:
526:
525:
522:
517:
514:
513:
509:
504:
501:
500:
492:
487:
481:
480:
476:
471:
465:
464:
461:
456:
453:
452:
449:
444:
441:
440:
437:
435:
429:
428:
425:
422:
403:
400:
373:
370:
369:
368:
362:
356:
349:
338:
335:
322:
321:
308:
305:
302:
287:
284:
239:
236:
199:
198:
186:
167:
164:
114:
111:
109:
106:
81:for Hayes and
44:AT command set
26:
9:
6:
4:
3:
2:
2380:
2369:
2366:
2364:
2361:
2360:
2358:
2343:
2340:
2338:
2335:
2333:
2330:
2328:
2325:
2323:
2320:
2318:
2315:
2314:
2311:
2306:
2298:
2293:
2291:
2286:
2284:
2279:
2278:
2275:
2268:
2264:
2261:
2259:
2256:
2254:
2250:
2247:
2244:
2242:
2239:
2237:
2234:
2231:
2228:
2226:
2222:
2219:
2216:
2214:
2210:
2206:
2203:
2201:
2197:
2194:
2191:
2189:
2186:
2184:
2181:
2180:
2167:
2161:
2149:
2142:
2136:
2127:
2123:
2117:
2115:
2099:
2093:
2079:
2075:
2069:
2061:
2057:
2050:
2044:
2030:on 2009-03-10
2029:
2025:
2019:
2013:
2008:
2001:
1997:
1994:
1988:
1973:
1971:
1966:
1959:
1951:
1945:
1937:
1936:
1935:Computerworld
1928:
1913:
1906:
1899:
1895:
1894:
1889:
1882:
1880:
1875:
1862:
1858:
1855:
1852:
1851:
1849:
1846:
1844:
1841:
1838:
1835:
1834:
1828:
1824:
1814:
1812:
1806:
1799:
1795:
1792:
1791:
1787:
1784:
1783:
1779:
1775:
1771:
1768:
1767:
1763:
1760:
1759:
1755:
1751:
1748:
1747:
1743:
1740:
1739:
1735:
1732:
1731:
1727:
1724:
1723:
1720:
1716:
1713:
1712:
1708:
1705:
1704:
1701:
1698:
1696:
1692:
1677:
1674:
1673:
1669:
1666:
1665:
1661:
1658:
1657:
1653:
1650:
1649:
1645:
1642:
1641:
1637:
1634:
1633:
1629:
1626:
1625:
1621:
1618:
1617:
1613:
1610:
1609:
1605:
1602:
1601:
1597:
1594:
1593:
1589:
1586:
1585:
1581:
1578:
1577:
1573:
1568:
1567:
1559:
1557:
1553:
1549:
1545:
1541:
1526:
1523:
1520:
1517:
1516:
1512:
1507:
1504:
1501:
1498:
1495:
1492:
1489:
1486:
1483:
1480:
1479:
1478:
1474:
1471:
1468:
1467:
1463:
1460:
1457:
1454:
1453:
1449:
1446:
1443:
1440:
1439:
1435:
1432:
1430:Delay to DTR
1429:
1426:
1425:
1421:
1418:
1415:
1412:
1411:
1407:
1404:
1401:
1398:
1397:
1393:
1390:
1387:
1384:
1383:
1379:
1376:
1373:
1370:
1369:
1365:
1362:
1359:
1356:
1355:
1351:
1348:
1345:
1342:
1341:
1337:
1334:
1331:
1328:
1327:
1323:
1320:
1317:
1314:
1313:
1309:
1306:
1303:
1300:
1299:
1295:
1292:
1289:
1286:
1285:
1281:
1278:
1275:
1272:
1271:
1267:
1264:
1261:
1258:
1257:
1253:
1250:
1248:Ring Counter
1247:
1244:
1243:
1239:
1236:
1233:
1230:
1229:
1225:
1222:
1219:
1216:
1215:
1207:
1205:
1201:
1197:
1193:
1189:
1184:
1176:
1172:
1168:
1164:
1161:
1159:
1155:
1152:
1151:
1147:
1145:
1143:
1140:
1139:
1135:
1133:
1131:
1128:
1127:
1123:
1119:
1117:
1115:
1112:
1111:
1103:
1101:
1099:
1096:
1095:
1091:
1088:
1086:
1082:
1079:
1078:
1073:
1060:
1058:
1056:
1053:
1052:
1048:
1045:
1043:
1039:
1036:
1035:
1031:
1030:
1023:in it. Using
1022:
1018:
1014:
1012:
1011:
1005:
998:
997:
993:
989:
985:
983:
981:
974:
973:
969:
965:
963:
961:
957:
951:
947:
946:
934:
933:
926:
925:
921:
918:
916:
913:
912:
904:
901:
899:
895:
892:
891:
887:
884:
882:
879:
878:
870:
868:
866:
863:
862:
858:
856:
854:
851:
850:
846:
843:
840:
838:
834:
831:
830:
826:
822:
819:
815:
812:
811:
807:
806:Plug-and-play
802:
799:
797:
793:
790:
789:
785:
782:
780:
777:
776:
772:
769:
767:
763:
760:
759:
755:
752:
750:
747:
746:
742:
739:
737:
733:
730:
729:
726:
705:
702:
700:
697:
696:
692:
688:
685:
683:
680:
679:
675:
672:
670:
666:
663:
662:
658:
655:
652:
651:
648:
640:
638:
634:
630:
626:
622:
618:
617:
612:
607:
597:
589:
585:
582:
577:
573:
572:
571:
569:
562:Compatibility
554:
550:
548:
545:
543:
540:
539:
535:
533:
530:
528:
527:
523:
521:
518:
516:
515:
510:
508:
505:
503:
502:
498:
493:
491:
488:
486:
483:
482:
477:
475:
472:
470:
467:
466:
462:
460:
457:
455:
454:
450:
448:
445:
443:
442:
438:
436:
434:
431:
430:
426:
423:
420:
419:
416:
414:
409:
399:
397:
393:
389:
384:&C1S0=0X4
383:
382:
363:
357:
350:
344:
343:
342:
334:
331:
326:
318:
313:
309:
306:
303:
300:
299:
298:
295:
293:
283:
281:
277:
276:U.S. Robotics
273:
268:
266:
262:
258:
254:
248:
245:
235:
233:
228:
227:ping of death
223:
219:
214:
212:
208:
204:
196:
192:
191:
187:
184:
183:
179:
178:
177:
173:
163:
160:
155:
152:
148:
144:
139:
137:
133:
127:
124:
120:
105:
103:
98:
96:
92:
84:
74:
70:
68:
65:
61:
57:
53:
49:
45:
41:
32:
19:
2341:
2160:
2148:the original
2135:
2126:the original
2102:. Retrieved
2092:
2081:. Retrieved
2077:
2068:
2055:
2043:
2032:. Retrieved
2028:the original
2018:
2007:
1987:
1975:. Retrieved
1972:mailing list
1968:
1958:
1944:
1933:
1927:
1915:. Retrieved
1905:
1897:
1891:
1826:
1807:
1804:
1714:AT+CPIN=1234
1709:Description
1699:
1688:
1662:Test issues
1555:
1551:
1547:
1537:
1476:
1464:0 (disable)
1251:0–255 rings
1203:
1199:
1195:
1191:
1185:
1182:
1174:
1170:
1166:
1157:
1153:
1141:
1129:
1121:
1113:
1106:CONNECT 1200
1097:
1084:
1080:
1054:
1041:
1037:
1026:
1024:
1020:
1016:
1007:
1001:
999:
991:
987:
977:
975:
967:
959:
953:
949:
942:
940:
938:
929:
927:
914:
897:
893:
880:
864:
852:
844:
836:
832:
817:
813:
795:
791:
783:Hook status
778:
770:Hook Status
765:
761:
748:
735:
731:
708:
698:
690:
681:
668:
664:
656:Description
646:
632:
628:
624:
620:
614:
603:
594:
587:
580:
567:
565:
546:
541:
531:
519:
506:
489:
484:
473:
468:
458:
446:
432:
405:
396:concatenated
387:
380:
379:
375:
340:
327:
323:
316:
296:
291:
289:
269:
264:
260:
249:
243:
241:
215:
210:
200:
190:command mode
188:
180:
175:
156:
140:
132:input/output
128:
116:
101:
99:
75:
71:
56:Dennis Hayes
43:
39:
37:
1798:PDP context
1571:characters
1527:20 seconds
1416:Test Timer
1220:Description
1089:Smartmodem
919:Quiet Mode
902:Quiet Mode
820:(n=1 to 3)
359:<...>
292:AT commands
286:Description
265:TIA/EIA-602
2357:Categories
2104:2016-09-12
2083:2016-05-15
2034:2008-04-09
1977:8 December
1917:January 8,
1422:0 seconds
1190:character
1072:NO CARRIER
962:commands.
939:Note that
633:italicized
553:NO CARRIER
542:NO CARRIER
499:setting).
497:local echo
398:commands.
352:<LF>
346:<CR>
154:manually.
113:Background
100:The term "
2307:standards
1761:AT+COPS=?
1268:43 ("+")
659:Comments
575:timeouts.
182:data mode
69:in 1981.
2249:Archived
2221:Archived
2205:3gpp.org
2196:Archived
1996:Archived
1831:See also
1796:Defines
1741:AT&V
1719:PIN code
1548:V.25 ter
1217:Register
1046:Verbose
740:No Echo
653:Command
637:syncword
627:00101010
623:10000010
600:Autobaud
427:Comment
378:AT&F
312:register
272:Microcom
238:Commands
91:Microcom
58:for the
2327:K56flex
2078:PICList
1970:Bugtraq
1856:(video)
1785:ATD*99#
1744:Status
1706:Command
1569:Leading
1063:CONNECT
873:CONNECT
676:
474:CONNECT
469:CONNECT
424:Modem B
421:Modem A
381:&D2
280:Telebit
108:History
2363:Modems
2269:(dead)
2232:(dead)
2002:, 1993
1859:T.31 (
1769:AT+CSQ
1717:Enter
1202:. The
1175:&F
1162:Reset
1075:etc.)
568:per se
490:abcdef
485:abcdef
320:model.
255:(TIA)/
211:online
136:RS-232
85:, and
2305:modem
2267:Telit
2265:from
2151:(PDF)
2144:(PDF)
2060:ITU-T
2052:(PDF)
1854:H.324
1848:ITU-T
1839:(APN)
1556:V.251
1552:V.250
1540:ITU-T
1534:V.250
1475:0–10
1223:Range
1200:Reset
1188:tilde
952:and =
753:Echo
703:Dial
616:8-N-1
586:Many
317:S7=60
195:local
79:&
67:modem
2322:V.92
2209:3GPP
1979:2012
1919:2015
1774:rssi
1754:IMEI
1538:The
1518:S38
1469:S37
1455:S30
1441:S26
1427:S25
1413:S18
1399:S12
1385:S11
1371:S10
1067:BUSY
447:RING
392:DCEs
278:and
232:ICMP
157:The
89:for
64:baud
62:300
54:and
38:The
2337:MNP
1861:fax
1778:ber
1749:ATI
1691:GSM
1685:GSM
1357:S9
1343:S8
1338:50
1329:S7
1315:S6
1301:S5
1287:S4
1273:S3
1259:S2
1245:S1
1231:S0
1167:Z0'
1156:or
1122:ATO
1083:or
1040:or
896:or
835:or
816:or
794:to
764:or
734:or
667:or
532:ATH
507:+++
459:ATA
83:USR
2359::
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1635:+M
1627:+I
1619:+G
1611:+F
1603:+E
1595:+D
1587:+C
1579:+A
1546:,
1513:0
1436:5
1352:2
1324:2
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1240:0
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818:Ln
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1006:=
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1000:S
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988:n
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955:r
950:?
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931:n
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881:O
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699:D
669:A
629:1
621:0
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